Breeding pigs with improved disease resilience

The "ability to maintain a relatively undepressed production level while infected" was defined as resilience by Albers et al. (1984). In sheep breeding, selection for resistance versus resilience to nematode challenge has been well investigated. A third avenue is breeding for disease tolerance. Differences between disease resistance and disease tolerance have been outlined by Guy et al. (2012) in this workshop. Specific definitions and measurements of resilience used by various authors were discussed by Bisset and Morris (1996), who pointed out that both resistance and tolerance mechanisms may contribute to the expression of resilience, when it is defined in terms of productivity relative to a standard challenge level. This definition of disease resilience also implies that information is required about productivity, health and physiology of pigs, as well as measures of the environment to quantify the challenge level that pigs experienced.